Electromagnetically actuable brake device

ABSTRACT

An electromagnetically actuable brake device includes: a coil shell, in particular of the solenoid, an armature disk, which is connected to the coil shell in a torque-proof yet displaceable manner, a sensor having a sensor housing, a spring part, and a screwed cable gland. The coil shell has a stepped through bore, the sensor housing of the sensor has a stepped configuration, the screwed cable gland is situated at an end of the bore, in particular is screwed into a threaded section of the bore, the spring part is situated in the bore between the screwed cable gland and the sensor housing, the spring part is braced on a step of the sensor housing on one side and on the screwed cable gland on the other, and the sensor housing is pressed against a step of the bore, in particular by the spring part.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/536,103, which is the national stage of PCT/EP2015/002278,having an international filing date of Nov. 13, 2015, and claimspriority to Application No. 10 2014 018 485.4, filed in the FederalRepublic of Germany on Dec. 16, 2014, each of which is expresslyincorporated herein in its entirety by reference thereto.

FIELD OF THE INVENTION

The present invention relates to an electromagnetically actuable brakedevice.

BACKGROUND INFORMATION

It is generally known that brake devices are subject to wear.

SUMMARY

Therefore, example embodiments of the present invention provide forincreasing the safety in brake devices in the most compact mannerpossible.

Among features of an electromagnetically actuable brake device accordingto an example embodiment of the present invention are that the deviceincludes:

-   -   a coil shell, in particular of the solenoid,    -   an armature disk, which is joined to the coil shell in a        torque-proof yet displaceable manner,    -   a sensor including a sensor housing,    -   a spring part, and    -   a screwed cable gland.

The coil shell has a stepped through bore.

The sensor housing of the sensor has a stepped design.

The screwed cable gland is situated at an end of the bore and, inparticular, is screwed into a threaded section of the bore.

The spring part is situated in the bore between the screwed cable glandand the sensor housing.

The spring part is braced on a step of the sensor housing on one sideand braced on the screwed cable gland on the other.

The sensor housing is pressed against a step of the bore, in particularby the spring part.

This has the advantage that the sensor is able to be used for monitoringthe function and wear and that the solution is compact because thesensor together with the press-on device is integrated into the brake.The sensor may be arranged as an eddy-current sensor. The spring partpresses the sensor against a step of the bore, the spring being bracedon a screwed cable gland through which the sensor cable is routed to theoutside, this passage being arranged as a sealed passage. In addition,the screwed cable gland tightly seals the bore. The sensor makes itpossible to sense the distance from the sensor to the armature disk, inparticular in the non-energized state of the coil, the coil, insertedinto the coil shell, attracting the armature disk to the coil shell whenenergized. This is so because in the absence of a current supply, springelements push the armature disk away from the coil shell, and thus awayfrom the sensor, up to the stop on a brake-pad carrier carrying brakepads, whereupon the brake-pad carrier is pressed onto a part having acounter-brake surface.

Thus, there is no need to enlarge the brake in order to use the sensor,and the sensor is able to be placed inside the protected brake housing.

Among features of an electromagnetically actuable brake device accordingto an example embodiment of the present invention are that the deviceincludes:

-   -   a first and a second coil shell,    -   a first armature disk, which is connected to the first coil        shell in a torque-proof yet displaceable manner,    -   a second armature disk, which is connected to the second coil        shell in a torque-proof yet displaceable manner,    -   a sensor having a sensor housing, a spring part, and    -   a screwed cable gland.

The first and the second coil shell each have a through bore, the twobores being aligned coaxially with respect to each other, or in otherwords, the two bores therefore having in particular the same radialdistance from a shaft to be braked and covering the same peripheralangular range.

The bore in the second coil shell has a stepped configuration.

The sensor housing of the sensor has a stepped configuration.

The screwed cable gland is situated at the end, facing away from thesecond coil shell, of the bore in the first coil shell, and inparticular is screwed into a threaded section of the bore.

The spring part is situated in the first or the second bore, between thescrewed cable gland and the sensor housing.

The spring part is braced on a step of the sensor housing on one sideand on a sleeve, which touches the screwed cable gland at its end facingaway from the spring part, on the other.

The spring part is braced on the screwed cable gland on one side and ona sleeve, which touches a step of the sensor housing on the other.

The sensor housing is pressed against a step of the bore, in particularby the spring part.

This has the advantage that in the case of a dual brake, the sensor isable to be placed in a second brake, and the screwed cable gland is ableto be placed in a first brake. A sleeve situated between the spring partand its bracing point extends the manageable distance between thescrewed cable gland and the sensor. It is therefore possible to routethe bore through the first coil shell, the second coil shell, and thearmature disk of the first brake.

The axial range covered by the sleeve may overlap with the axial rangecovered by the first and the second coil shell. This is consideredadvantageous insofar as a great distance is able to be obtained.

The sleeve may project through a through bore of the first armaturedisk. This is considered advantageous insofar as it allows for a compactdesign of the brake.

The sleeve may be situated at a greater radial distance from the axis ofthe shaft to be braked than a brake-pad carrier which is connected in atorque-proof yet axially displaceable manner to the shaft to be braked.This has the advantage that the sleeve is situated within the brake and,in particular, is also at least partially situated in one or a pluralityof bore(s) but still does not hamper the rotational motion of thebrake-pad carrier.

A cover may be connected to the first and the second coil shell so thatthe intermediate region between the first and the second coil shell isenclosed in the manner of a housing, in particular, the first armaturedisk being situated in the intermediate region. This is consideredadvantageous insofar as the interior space of the brake, and thus alsothe sensor situated in the interior, is surrounded in the manner of ahousing.

A second cover may be connected to the second coil shell and to the parthaving a counter-brake surface, so that the intermediate region betweenthe part and the second coil shell is surrounded in the manner of ahousing, in particular the second armature disk being situated in theintermediate region. This has the advantage that the interior space ofthe second brake together with the sensor situated there is alsosurrounded in the manner of a housing.

The first and/or the second cover may be made from a more elasticmaterial than the coil shells, especially from plastic or rubber. Thishas the advantage that a nonpositive connection of a highly protectivetype is able to be created.

The sensor and the bore may be disposed at a greater radial distancefrom the axis of the shaft to be braked than a coil of the solenoid,that is to say, in particular the electromagnetically actuable brakedevice. This has the advantage that the sensor is integrated into thebrake but no modification is required at the coil.

The armature disk may be able to cover the bore, especially when thearmature disk is resting against the coil shell. This has the advantagethat when energy is supplied to the coil, the armature is attracted tothe coil shell and thus, also to the sensor. As a result, the armaturedisk covers the bore since it is larger than the bore cross-section.

The peripheral angular range covered by the armature disk may cover theperipheral angular range covered by the bore, and the radial distancerange covered by the armature disk may cover the radial distance rangecovered by the bore, in particular no part being situated in theintermediate region between the armature disk and the sensor. This hasthe advantage that the armature disk covers the bore when the coil isenergized and the armature disk is therefore pulled in the direction ofthe coil shell.

A cable may be centrically routed from the sensor through the springpart and centrically through the screwed cable gland. This is consideredadvantageous insofar as it allows for a simple cable layout.

The sensor may be arranged as an eddy-current sensor, in particular forsensing the distance between the armature disk and the eddy-currentsensor. This has the advantage that a very high resolution is able to beachieved when sensing the position of the armature disk.

Further features and aspects of example embodiments of the presentinvention are discussed in greater detail below with reference to theappended Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a brake device according to an example embodiment of thepresent invention including a sensor for wear detection, in a sectionalview.

FIG. 2 shows the sensor with an associated mounting system in an obliqueview.

FIG. 3 shows an alternative brake device equipped with a sensor for weardetection, in a sectional view.

FIG. 4 shows the sensor associated with FIG. 3 with an associatedmounting system, in an oblique view.

DETAILED DESCRIPTION

As illustrated in FIG. 1 and FIG. 2, an electromagnetically actuablebrake according to an example embodiment of the present invention isdepicted.

A brake-pad carrier 11 is connected to a shaft to be braked in atorque-proof yet axially displaceable manner. The shaft is mountedinside a housing part that is connected to coil shell 3 of a solenoid ina torque-proof manner.

Brake-pad carrier 11 has an internal tooth system which is in engagementwith an external tooth system disposed on the shaft. The tooth systemextends in the axial direction so that brake-pad carrier 11 is able tobe axially displaced in relation to the shaft.

A coil brace 6, in which an energizable coil 7 is situated, isaccommodated in an annular groove of coil shell 3. The ring axis of theannular groove is aligned coaxially with respect to the shaft axis.

Brake-pad carrier 11 is provided with brake pads 9 axially on bothsides. An armature disk 8 is situated axially between brake-pad carrier11 and coil shell 3. For example, armature disk 8 is made from aferromagnetic material. Armature disk 8 is connected to coil shell 3 ina torque-proof yet axially displaceable manner with the aid of guideelements, the armature disk being guided by the guide elements duringthe displacement.

Spring elements are situated between coil shell 3 and armature disk 8.An approach of armature disk 8 toward coil shell 3 can therefore onlytake place counter to the force generated by the spring elements.

When coil 7 is energized, armature disk 8 is pulled toward coil shell 3counter to the spring force generated by the spring elements.

In the non-energized state of coil 7, the spring elements axially pressarmature disk 8 in the direction of brake-pad carrier 11, the latterbeing axially displaced in the process and pressed against a part 10,which has a brake surface and is firmly connected to coil shell 3.

In other words, in the non-energized state of coil shell 7, armaturedisk 8 is pushed away from coil shell 3 up to an axial stop position.The stop position is a function of the thickness of the brake pads.Depending on the wear, the axial distance between armature 8 and coilshell 3 thus differs in the non-energized state.

To monitor wear, a sensor is provided for sensing this distance.

The sensor is arranged as an eddy-current sensor.

The housing of the sensor has a stepped outer contour.

A through bore, in which the sensor is accommodated, is situated in coilshell 3. The bore also has a stepped configuration and has across-section that tapers in the direction of the armature disk. Via acorresponding step, housing 1 of the sensor rests against the step ofthe bore and includes a step 20 on the side facing away from this stepand/or on the side facing away from armature disk 8. This step 20 leadsfrom a first diameter to a second diameter which is smaller than thefirst diameter. The axial end region tapering in this manner is disposedat the end of sensor housing 1 facing away from armature disk 8.

Sensor housing 1 may be arranged as a rotating body.

Sensor cable 5 is centrally routed out of sensor housing 1. A springpart 2, arranged as a spiral spring, is accommodated in the bore andbraced on step 20 of sensor housing 1. The end of the bore that facesaway from armature disk 8 is sealed with the aid of a screwed cablegland 4, which presses against the end of spring part 2 facing away fromstep 20. Screwed cable gland 4 is connected by screws to an internalthreaded section of the bore, or stated another way, is screwed into thebore.

The internal threaded section extends only across an end section of thebore and not across the entire bore. This end section of the bore issituated in the end region of the bore that faces away from armaturedisk 8.

Screwed cable gland 4 may be formed of metal.

In the same manner, sensor housing 1 and spring part 2 are made frommetal.

When screwing screwed cable gland 4 into the bore, spring part 2 istensioned and thus presses against sensor housing 1. Because of thepreloading created in this manner, the sensor housing 1 is pressedagainst the step of the bore.

Cable 5 is axially routed through spring part 2 in a centered manner andis then centrically routed through a recess in screwed cable gland 4 inthe axial direction.

Screwed cable gland 4 has a hexagonal shoulder 21, which limits thescrewing-in of screwed cable gland 4 and is furthermore suitable for thepositive application of an open end wrench. This makes it easy to screwscrewed cable gland 4 into the threaded section of the bore.

In contrast to the exemplary embodiment according to FIGS. 1 and 2, inthe exemplary embodiment according to FIGS. 3 and 4 a sleeve 30 forspacing spring part 2 apart from sensor housing 1 is placed inside thebore.

In this way the sensor is able to be installed on a second brakesituated at a greater distance, sleeve 30 bridging a first brake.

As illustrated in FIGS. 3 and 4, a first and a secondelectromagnetically operable brake are provided in the double brake.

The first brake is arranged according to FIG. 1. The second brake has asimilar configuration; here, the part of the second brake having acounter-brake surface is not a coil shell or need not be a coil shell,but may exemplarily be arranged as a bearing shield of an electricmotor.

In this case, a second coil shell 36 is used as the particular part 10that has a brake surface for brake-pad carrier 11 with brake pad 9.Second coil shell 36 is firmly connected to coil shell 3 of the firstbrake, in particular connected with the aid of screws.

Another annular groove, its ring axis being aligned coaxially with theshaft axis, is also situated in second coil shell 36.

Once again, a coil brace 34, which accommodates a second coil 35, isaccommodated in the annular groove of second coil shell 36.

A second brake-pad carrier 11 is connected to the shaft in atorque-proof yet axially displaceable manner; the shaft has an axiallyextending external tooth system for this purpose, which is in engagementwith an internal tooth system of brake-pad carrier 11. An armature disk33 is axially situated between the second brake-pad carrier and secondcoil shell 36 and connected to second coil shell 36 in a torque-proofyet axially displaceable manner with the aid of guide elements.

Second spring elements are situated between second armature disk 33 andsecond coil shell 36 so that when second coil 35 is energized, armaturedisk 33 is pulled toward coil shell 36 counter to the spring forcegenerated by the second spring elements. In the non-energized state ofsecond coil 35, second armature disk 33 is axially pushed away fromsecond coil shell 36 and onto the second brake-pad carrier with brakepads. The second brake-pad carrier in turn is axially pressed onto apart having a counter-brake surface, the part being situated on the sideof the second brake-pad carrier axially facing away from armature disk33.

A sensor for wear detection of the brake pads of the second brake is inturn disposed in a bore that is situated in coil shell 36 in an axiallyuninterrupted manner and has a stepped configuration; the narrowerand/or tapered section of the bore is situated on the side facing secondarmature disk 33, and the section having the larger cross-section issituated on the side facing second armature disk 33.

The bore, so to speak, continues through armature disk 8 of the firstbrake and through coil shell 3 of the first brake. The bores in armaturedisk 8 and coil shell 3 have a coaxial alignment and are arranged usingat least the same cross-section.

Thus, sensor housing 1 is pressed against the step of the boreimplemented in second coil shell 36, and a corresponding step of thesensor housing is placed against the step of the bore introduced intosecond coil shell 36, or in other words, is pressed against it.

A spring part 2 is in turn pressing against step 20 of sensor housing I;however, at its axial end facing away from sensor housing 1, spring part2 is braced on a sleeve 30, which is in turn braced at its axial endfacing away from spring part 2 on screwed cable gland 4, which isscrewed into coil shell 3 in the threaded section.

This screwed cable gland is in turn resting against coil shell 3 via itsshoulder Sleeve 30 is hollow. Thus, cable 5 is centrically routedthrough spring part 2 and sleeve 30 so that it is likewise able to becentrically routed through the screwed cable gland and out of theinterior space of the brake device in a sealed manner.

The bore and sleeve 30 are situated at a radial distance from the shaftaxis such that brake-pad carrier 11 together with brake pads 9 isradially situated within the bore and sleeve 30. The axial range coveredby sleeve 30 covers the axial range covered by armature disk 8 and theaxial range covered by brake-pad carrier 11 with brake pads 9, and itoverlaps with the axial range covered by coil shell 3 and by second coilshell 36.

Coil shell 3 and second coil shell 36 are connected with the aid of acover 31, especially a rubber cover, so that the intermediate regionsituated axially between coil shell 3 and coil shell 36 is covered inthe manner of a housing. Cover 31 has an annular design for this purposeand is placed in a nonpositive manner onto a subregion of the externalsurface of coil shell 3 and coil shell 36.

Situated in the intermediate region are brake-pad carrier 11 togetherwith brake pads 9 and armature disk 8. The region axially covered bycover 31 therefore covers the axial region covered by brake-pad carrier11 together with brake pads 9 and the axial region covered by armaturedisk 8.

In addition, when viewed from the direction of the shaft axis, cover 31is situated radially outside brake-pad carrier 11 together with brakepads 9 and armature disk 8.

Coil shell 36 and the part having the counter-brake surface aresimilarly connected with the aid of a cover 32, in particular a rubbercover, so that the second intermediate region that is situated axiallybetween second coil shell 36 and the part having the counter-brakesurface is covered in the manner of a housing. Cover 32 has an annulardesign for this purpose and is placed in a nonpositive manner on asubregion of the external surface of coil shell 36 and of the parthaving the counter-brake surface.

Situated in the second intermediate region are the second brake-padcarrier together with the brake pads and second armature disk 33. As aresult, the region axially covered by cover 32 covers the axial regioncovered by the second brake-pad carrier together with the brake pads andthe axial region covered by armature disk 33.

In addition, when viewed from the direction of the shaft axis, cover 32is situated radially outside the second brake-pad carrier together withthe brake pads and armature disk 33.

Cover 31 may be arranged in the same manner as cover 32. As a result,only one type of cover needs to be stocked.

Sleeve 30 is situated at a greater radial distance than coil 7, coilshell 6 and/or the annular groove in coil shell 3 and/or the annulargroove in coil shell 36.

LIST OF REFERENCE NUMERALS

-   1 Sensor housing, stepped configuration-   2 Spring part-   3 Coil shell-   4 Screwed cable gland-   5 Cable-   6 Coil brace-   7 Coil, in particular brake coil-   8 Armature disk-   9 Brake pad-   10 Part having the brake surface-   11 Brake-pad carrier-   20 Step-   21 Shoulder-   30 Sleeve-   31 Cover, in particular rubber cover-   32 Cover, in particular rubber cover-   33 Further armature disk-   34 Further coil brace-   35 Further coil-   36 Further coil shell

What is claimed is:
 1. A sensor system for an electromagneticallyactuable brake device, comprising: a coil shell including a steppedthrough bore; a sensor including a stepped sensor housing; and a springpart arranged in the bore and pressing the sensor housing against a stepof the stepped through bore.
 2. The sensor system according to claim 1,wherein one side of the spring part is braced on a step of the sensorhousing.
 3. The sensor system according to claim 1, wherein the steppedthrough bore transitions at the step from a first diameter to a seconddiameter, the second diameter being smaller than the first diameter. 4.The sensor system according to claim 3, wherein the sensor housingincludes a step, the sensor housing having a first diameter on a firstside of the step of the sensor housing and a second diameter on secondside, opposite the first side, of the step of the sensor housing.
 5. Thesensor system according to claim 4, wherein the first diameter of thesensor housing is smaller than the first diameter of the stepped throughbore, and the second diameter of the sensor housing is smaller than thesecond diameter of the stepped through bore.
 6. The sensor systemaccording to claim 1, wherein a portion of the sensor housing having thefirst diameter is arranged in a portion of the stepped through borehaving the first diameter, and wherein a portion of the sensor housinghaving the second diameter is arranged in a portion of the steppedthrough bore having the second diameter.
 7. The sensor system accordingto claim 4, wherein the spring part presses the step of the sensorhousing against the step of the stepped through bore.
 8. The sensorsystem according to claim 1, wherein the sensor housing includes a firststep and a second step, the spring part pressing the first step againstthe step of the stepped through bore and being braced against the secondstep of the sensor housing.
 9. The sensor system according to claim 1,further comprising a screwed cable gland arranged at an end of thestepped through bore, the spring part being arranged between the screwedcable gland and the sensor housing.
 10. The sensor system according toclaim 1, wherein the sensor is arranged as an eddy-current sensor. 11.The sensor system according to claim 1, wherein the sensor is adapted tosense a distance between an armature disk of the brake device and thesensor.
 12. The sensor system according to claim 9, wherein the screwedcable gland is screwed into a threaded section of the stepped throughbore.
 13. The sensor system according to claim 1, wherein the sensor andthe stepped through bore are located at a greater radial distance froman axis of a shaft of the brake device to be braked than a coil of asolenoid of the brake device.
 14. The sensor system according to claim1, further comprising a cable centrically routed from the sensor throughthe spring part.
 15. The sensor system according to claim 14, furthercomprising a screwed cable gland arranged at an end of the steppedthrough hole, the spring part being arranged between the screwed cablegland and the sensor housing, the cable being arranged centricallythrough the screwed cable gland.
 16. The sensor system according toclaim 1, wherein the sensor is adapted to monitor wear of a brake pad ofthe brake system by sensing an axial distance between an armature of thebrake system and the coil shell.
 17. The sensor system according toclaim 1, wherein the spring part is arranged as a helical spring. 18.The sensor system according to claim 1, wherein the step is arranged ata first end of the stepped through bore.
 19. The sensor system accordingto claim 18, further comprising a screwed cable gland arranged at asecond end of the stepped through bore opposite the first end, thespring part being arranged between the screwed cable gland and thesensor housing.
 20. The sensor system according to claim 9, wherein thescrewed cable gland includes a hexagonal shoulder engaging against asurface of the coil shell.